Important Practice Questions on AVERAGE SPEED (1)
Duration: 9 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- Paper 1 | Reasoning Test: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Seating Arrangements, Blood Relations, Puzzle Solving (Puzzles), Venn Diagram, Analogy, Ranking, Order and Sequence, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Cubes & Dices, Analytical Reasoning (Counting Figures Reasoning), Calendar, Alphabet and Word Tests, Numerical Reasoning, Number System, Averages, Mixtures and Alligation, Percentages, Series Completion, Analogy and Classification, Patterns in Two-Dimensional Figures, Coding and Decoding, Mathematical Operations, Direction Sense, Algebra, Logical Deduction and Induction, Syllogisms and Venn Diagrams, Critical Reasoning, Order, Ranking and Sequence, Reading Comprehension, Profit, Loss and Discount, Constraint Puzzles, Speed, Time and Distance, Traverse Surveying, Ratio and Proportion, Time and Work, Mensuration, Permutations and Combinations, Clocks and Calendars, Data Interpretation, Assembling and Grouping of Shapes, Transformation of Shapes, Three-Dimensional Patterns and Visualization, Cubes and Dice, Vocabulary, Blood Relations, Data Sufficiency
- Paper 1 | Numerical Analysis: Number System, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Sequence and Series (Series), Powers and Exponents (Surds and Indices), Algebra, Statistics, Data Interpretation, Mental Ability, Arithmetic, Logarithm, Profit and Loss, Simple Interest and Compound Interest, Speed Time and Distance, Mixture and Alligation, Mensuration and Geometry, Permutation and Combination, Probability, Sequences and Series, Powers, Surds and Logarithms, Subject-Verb Agreement, Sentence Completion, Geometry, Sentence Structure and Correction, Data Sufficiency, Trigonometry, Measurement and Quantity Take-Off, Signal Space and Optimum Detection, Probability, Statistics, Algebra, Time and Work, Speed, Time and Distance, Data Interpretation, Graph Theory, Combinatorics
- Paper 1 | General Knowledge: State Wise GK, History, Geography, GK- Current Affairs, Static General Knowledge, Polity, Indian Economy
- Paper 1 | DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Transaction Management, Concurrency Control, Relational Calculus, Database Security & Authorization, Database Recovery
- Paper 1 | Data Communication & Network: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Network Security, Security in Mobile and Wireless Computing, Input Output Organisation, File Management, Hardware Basics, Terms & Abbreviations, Protocols & Services, Network Access Technologies, Cyber Safety and Security, Basics of COA
- Paper 2 | System Analysis & Design: Fundamentals of Systems and Information Systems, SDLC and Development Approaches, Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Documentation and Software Requirements Specification (SRS), SDD and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Security, Risk Management & Maintenance, extras
- Paper 2 | Programming Language (Java): Java Fundamentals, OOPS with Java, Array, String, IO & References, Generic & Collections, Multithreading, Java, Miscellaneous, Control Flow, OOPS with C++, Stack, C Fundamentals, Arrays & Pointers, Object Oriented Technology, Control Flow & Looping, Introduction to Python
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video, presented by Yash Jain from Knowledge Gate, is a tutorial on calculating average speed for round trips where the speeds for the outbound and return journeys are different. The video begins with an introduction to the topic, followed by a detailed solution to a problem where a man travels to his office at 65 km/hr and returns at 75 km/hr. The instructor demonstrates the correct formula for average speed, which is the total distance divided by the total time, and shows that for a round trip, this simplifies to 2 * s1 * s2 / (s1 + s2). He then applies this formula to the given speeds, calculating the average speed as 69.6 km/hr. The lesson continues with a second example involving a cyclist traveling from point A to B at 28 km/hr and returning at 26 km/hr, for which he calculates the average speed to be 26.96 km/hr. The video concludes with a thank you message.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title slide featuring a space-themed graphic with the text 'SPEED, TIME & DISTANCE' and the hashtag '#knowledgegate'. This transitions to a presentation slide with the same title, crediting the instructor as 'By Yash Jain'. The instructor, Yash Jain, appears in a small window in the bottom right corner, introducing the topic of average speed for a round trip. He explains that the average speed is not the arithmetic mean of the two speeds but is calculated as the total distance divided by the total time. He states that for a round trip, the average speed can be found using the formula 2 * s1 * s2 / (s1 + s2).
2:00 – 5:00 02:00-05:00
The video presents the first problem: 'A man goes to his office from his home at a speed of 65 km/hr and returns at 75 km/hr. Find his average speed.' The instructor draws a diagram showing 'home' and 'office' with speeds of 65 km/hr and 75 km/hr respectively. He then writes the formula for average speed: 2 * s1 * s2 / (s1 + s2). He substitutes the values: 2 * 65 * 75 / (65 + 75). He calculates the numerator as 2 * 65 * 75 = 9750 and the denominator as 65 + 75 = 140. He then performs the division 9750 / 140, which he simplifies to 975 / 14, resulting in 69.6 km/hr. He confirms this is the correct average speed.
5:00 – 9:25 05:00-09:25
The video moves to a second example: 'A cyclist goes from point A to B at a speed of 28 km/hr and returns to point A at a speed of 26 km/hr. Find his average speed.' The instructor draws a diagram with points A and B and the respective speeds. He applies the same formula: 2 * s1 * s2 / (s1 + s2). He substitutes the values: 2 * 28 * 26 / (28 + 26). He calculates the numerator as 2 * 28 * 26 = 1456 and the denominator as 28 + 26 = 54. He then performs the division 1456 / 54, which he simplifies to 728 / 27, resulting in 26.96 km/hr. The video concludes with a thank you slide.
The video provides a clear and structured lesson on calculating average speed for a round trip. It emphasizes the correct method, which is to use the harmonic mean formula 2 * s1 * s2 / (s1 + s2), and explicitly warns against the common mistake of using the arithmetic mean. The instructor uses two distinct, real-world examples to demonstrate the application of this formula, ensuring the concept is well-understood. The progression from the general formula to its application in two different scenarios effectively reinforces the learning objective.

